This European Standard applies to electronic control equipment for heating systems with water as the heating medium and a flow water temperature up to 120 °C.

This control equipment controls and regulates the distribution and/or the generation of heat in relation to the outside temperature and time and other reference variables.

This standard covers also controllers which contain an integrated optimum start or an optimum start-stop control function.

Safety requirements on heating systems remain unaffected by this standard. The dynamic behaviour of the valves and actuators are not covered in this standard.

A multi-distribution and/or multi-generation system needs a coordinated solution to prevent undesired interaction and is not part of this standard.